If you’re sick of smoky casinos, head for the craps capital’s great outdoors. Hike, bike, chill. We’ll even throw in some Vegas-style glitter — at one pastoral state park, you can tour a rambling ranch house that recluse billionaire Howard Hughes once owned and where armed robbers stole a diamond ring Elizabeth Taylor later wore.

Ante up for this fresh-air adventure:

Red Rock Canyon National Conservation Area

Seriously, this is like journeying to Mars. Craggy crimson-colored sandstone monoliths soar up to 3,000 feet and change with the sun’s glow — often the rocks appear striped next to gray limestone formations created millions of years ago from compressed shells and marine skeletons (hard to imagine but this parched desert was once a deep ocean).

Spread throughout 195,819 acres, Red Rock is a geological wonder and recreational jackpot. There’s a 13-mile scenic drive, more than 30 miles of hiking trails, 2,000 rock-climbing routes, camping, mountain biking and horseback riding. We did the moderately strenuous 2.5-mile Calico Tanks Trail, which winds past the site of an early Native American roasting pit and on to a dramatic overlook where we gazed out at the far-off cement-jungle Strip and savored the absurd contrast. (This trail does require scampering over boulders — or on the return trip, scooting down on your rear).

You quickly get the vibe others were at Red Rock long before you — Native American rock-art petroglyphs decorate various areas. And last year, hikers discovered three-toed fossilized dinosaur tracks.

Spring Mountain Ranch State Park

Founded as a ranch in 1876, this 520-acre oasis has a crazy rich history. Vacationers can picnic in the expansive grassy meadow, enjoy five easy trail hikes, encounter roaming wild burros and buy scorpion suckers at the gift shop. But the big payout is touring the six-bedroom, six-bath ranch house, which has separate rooms featuring furniture and mementos from seven colorful previous owners that include eccentric Hughes and “furrier-to-the-stars” Willard George. The latter tried to raise chinchillas on the land in the 1930s to keep clients such as Ingrid Bergman in animal stoles.

In 1955, four-time-divorced German actress Vera Krupp moved in after dumping her wealthy Nazi ammunitions-supplier husband. Krupp soon became a deputy sheriff — “I think she wanted to be able to enforce people from coming onto her property,” said state ranger Mandy Keefer.

Unfortunately, Krupp couldn’t do much when three armed robbers burst into the home, ripped her 33.6-karat emerald-cut diamond from her finger and tied her to a chair. Weeks later, cops recovered the stolen sparkler and returned it to Krupp.

After she died in 1968, the Krupp Diamond was sold at auction to Richard Burton as a gift for wife Liz Taylor. The acting icon wore it almost every day until her death last year.

Mount Charleston

The weird part is driving up a winding canyon to get here. Before your very eyes, an austere landscape of desert scrub and Joshua trees suddenly morphs into thick alpine forests.

You can hike more than 40 miles of trails, camp, picnic, horseback ride, and in the winter, snowboard and ski in this lush wilderness dominated by the 11,918-foot-high Mount Charleston peak. And you can also behold what’s considered the oldest living organisms on Earth.

That would be bristlecone pines. Take the moderate six-mile Bristlecone Trail, which meanders past ponderosa pines, white firs, and quaking aspens to an isolated hilltop grove of twisting bristlecone trees – a species believed to date back up to 5,000 years.

After your workout, retreat to the A-frame Mount Charleston Lodge and sip a Mountain Mai Tai while marveling at the sumptuous summit views from the deck. If your furry friend is along, order off the doggy menu — $5 for a pooch’s turkey burger, $2 for Milk Bones.

Springs Preserve

Smack-dab in the city, just down from a Circle K convenience store, is “the birthplace of Las Vegas.” From the street, you’d never imagine that beyond the gates is the 180-acre Springs Preserve, which is on the National Register of Historic Places. This is the site of the artesian springs that supplied the Vegas valley with water and where Spanish explorers, missionaries, and Native Americans all called home.

Today, you can tour a lovely 8-acre botanical garden that includes fanciful vegetable beds, before hoofing it along 3.65 miles of dusty trails past archeological sites (as you channel the settlers’ spirits, try to ignore the altitude-sickening Stratosphere casino in the near distance). While trekking, you’ll also see a burned-out caretakers’ house and rustic chicken coop from the 1940s railroad era.

“People live here all their lives and they’ve never even been here,” said Tyler Meadows, 53, as he finished a hike with two local friends. “It’s not all about gambling. I’d rather come here and walk and be quiet.”

Info: 333 S. Valley View Blvd., three miles from Strip; www.springspreserve.org, (702) 822-7700; free access to trails and garden but entry fee for museum and galleries.

Henderson Bird Viewing Preserve

This is something to tweet about. My outing began when “Feather Chaser” Je Anne Branca had me hop in the Birdmobile, a six-person golf cart that takes travelers throughout this tranquil 140-acre, nine-pond refuge in a semi-industrial area.

The gung-ho Branca is a docent and she quickly stopped the Birdmobile, whipped out a spotting scope and had me peer through at a splashing group of Ruddy Ducks.

“Birds can move every feather on their body individually,” informed Branca, who soon pointed out some of the 278 other species, including Killderes and double-crested cormorants.

With the use of free binoculars and docents like Branca who let fun facts fly — Wilson’s Phalarope males incubate and raise babies — you’d have to be a birdbrain not to come here.

Visitors from 83 countries have flocked to the sanctuary. “We thought all we’d see is casinos and that would be it,” said Jon Burrows, a London birder who scored the equivalent of a royal flush when he spotted an American avocet. “I never ever would’ve imagined this.”